Singing Teacher AND Vocal Coach?? Good or Bad idea??

I have singing lessons within my school at the moment. I tend to do more classical styled singing as they are for exam boards and such. However I've been told that there is a vocal coach which is really good at some studios, if i did have lessons it may only be 1 or 2 a month as they are £20 an hour but I think they'll be worthwhile, especially as I'm moving into the performance/rock/staged type singing with a band.

But I'm not sure whether or not having both would be beneficial to more, or whether it would be a bad idea or not. =S Could anyone help?

Thanks in advance xx